2565 has 16 divisors (see below), whose sum is σ = 4800.
Its totient is φ = 1296.
The previous prime is 2557. The next prime is 2579. The reversal of 2565 is 5652.
2565 = T6 + T7 + ... +
2565 is nontrivially palindromic in base 2 and base 8.
It is not a de Polignac number, because 2565 - 23 = 2557 is a prime.
It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.
It is an alternating number because its digits alternate between even and odd.
It is a plaindrome in base 12 and base 13.
It is a nialpdrome in base 15.
It is a zygodrome in base 4.
It is a congruent number.
It is an unprimeable number.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126 + ... + 144.
It is an arithmetic number, because the mean of its divisors is an integer number (300).
It is an amenable number.
2565 is a deficient number, since it is larger than the sum of its proper divisors (2235).
2565 is a wasteful number, since it uses less digits than its factorization.
2565 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 33 (or 27 counting only the distinct ones).
The product of its digits is 300, while the sum is 18.
The square root of 2565 is about 50.6458290484.
The cubic root of 2565 is about 13.6887079062.
The spelling of 2565 in words is "two thousand, five hundred sixty-five".